Hammer



FIG. 1 is a side elevational view of a hammer showing my new design, the opposite side being a mirror image;

FIG. 2 is a front elevational view thereof, the rear view being a mirror image;

FIG. 3 is a top plan view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a front perspective view thereof. 

The ornamental design for a hammer, as shown and described. 